Guidelines for looking at the antiphospholipid antibodies in systemic lupus erythematosus

Lupus anticoagulant (LA), anticardiolipin (aCL), and/or antiphospholipid (aPL) antibodies are the hallmarks of the antiphospholipid syndrome, characterized by widespread thrombosis. The syndrome has been described as primary or secondary when aCL/aPL are the only classes of detectable autoantibodies or occur in the context of systemic lupus erythematosus (SLE) or SLE-like disease. However, since LA/aCL/aPL have been extensively looked for, it has become evident that they may also be detected in the absence of any clinical correlation with thrombosis. In particular, among SLE patients, these antibodies mean a high risk of thrombosis only in a small subset, sharing clinical features with primary antiphospholipid syndrome. As laboratory examination is still unable to distinguish between high-risk and non-high-risk antiphospholipid antibodies, it is crucial to have some reasonable criteria able to guide the day-to-day clinical practice. We attempt to trace the following guidelines: (1) distinguish between transient and persistent LA/aCL/aPL results; (2) do not forget the LA phenomenon in the era of aCL/aPL; (3) maintain a strict communication with the laboratory; (4) exclude other causes of primary coagulation abnormalities; (5) look at the time of appearance of LA/aCL/aPL with respect to thrombosis; (6) analyze any possible laboratory clue putatively useful to distinguish between 'rouge' and 'non-rouge' LA/aCL/aPL; (7) look for signs of widespread noninflammatory vasculopathy; (8) do not engage a war to the knife against LA/aCL/aPL by immunosuppressive therapies.